Singer A M, Naimark A, Felson D, Shapiro J H
AJR Am J Roentgenol. 1985 May;144(5):973-5. doi: 10.2214/ajr.144.5.973.
Prompted by the failure to detect a clinically evident knee-joint effusion on the cross-table lateral view of an injured patient, a prospective study was carried out to compare the routine overhead and cross-table lateral knee views for detection of joint effusion in 18 patients with acute knee trauma. In every case, the size of the effusion as determined by the "fat-pad separation sign" was greater on the overhead view (p less than 0.001). In three patients the effusion would have been missed radiologically had the vertical-beam projection been omitted. The authors conclude that the cross-table lateral view is less sensitive than the routine overhead lateral view in the detection of knee-joint effusions because of fluid shift into the lateral recesses of the suprapatellar bursa with the patient in the supine position. This phenomenon is demonstrated by arthrography and computed tomography in one patient.
由于在受伤患者的髌下横断侧位片上未能检测到临床上明显的膝关节积液，因此开展了一项前瞻性研究，以比较常规的正位和髌下横断侧位膝关节片对18例急性膝关节创伤患者关节积液的检测情况。在每一例中，通过“脂肪垫分离征”确定的积液量在正位片上更大（p小于0.001）。在3例患者中，如果省略垂直投照，积液在放射学上就会漏诊。作者得出结论，由于患者仰卧时液体转移至上髌囊的外侧隐窝，髌下横断侧位片在检测膝关节积液方面不如常规正位侧位片敏感。在1例患者中，关节造影和计算机断层扫描证实了这一现象。
